17.9 Scenario questions

Q51. Pipeline is red — how do you debug?

Open the failed job; read the first real error; reproduce locally; check flaky vs real failure; fix or quarantine; do not bypass required checks.

Q52. Production latency spiked at lunch — what do you check?

Golden signals dashboard; recent deploy tag; error logs around the window; disk/CPU saturation; rollback if a bad SHA is implicated; write a short incident note.

Q53. Disk alert fired on a lab VM — steps?

Confirm df -h / inodes; find large logs/docker data; rotate/ship logs; delete safe temp fill files; fix root cause; confirm alert resolves.

Q54. Explain CI/CD to a project manager.

Every code change goes through an inspection belt: bad items stop the belt (tests). Only tagged finished builds go to production (deploy). If users hit errors, we bring back yesterday's known-good tag (rollback).

Q55. You find an AWS access key in a GitHub commit — what do you do?

Treat as compromised: revoke/rotate immediately in IAM; remove from history carefully; add .gitignore/scanning; never commit new keys; notify account owner/trainer.

Q56. Staging works, production fails after promote — ideas?

Config/env differences; secrets missing; migrations not run; data shape; feature flags; DNS/cache; confirm same artifact tag actually promoted.

Q57. Node Exporter target DOWN in Prometheus?

Check process listening, port, firewall/SG, scrape URL, and that you curl metrics successfully from the Prometheus host.

Q58. Service has no endpoints in Kubernetes?

Selector labels do not match Pod labels — fix labels; confirm Pods Ready.

Q59. First 90 days — what do juniors actually do?

Read runbooks; shadow on-call; fix small CI flakes; write docs; improve dashboards/alerts; own a narrow service path; ask clarifying questions; do not silent-hero production changes.

Q60. How do you present your portfolio?

Public/private GitHub repos with clear README, architecture sketch, SHA-tagged images story, Actions badge, screenshots of dashboard/health curl — no secrets, no PDF requirement for this course site. Link AWS/Cyber learning for cloud/security depth.